Why, if you have a floating container in your inventory, does it's weight still affect yours?

For example: there is one that, in it's description, says it floats and follows your every move. Technically you aren't holding or carrying it around, so why does it's weight still add to yours?

I won't lie, it'd be nice to have a container full of junk and never have to worry about the extra weight, which I imagine is probably your reason for not allowing this, but still, I'm curious.

If you are in a gravity free environment, having extra mass still makes it harder to change direction etc, despite that fact that said mass make me stuck to your hip, floating and following your every move.

If that is the case, it would make it harder to dodge etc, and thus in some ways is relevant.

nt